Operating mechanism for circuit breakers



July 10, 1956 c. J. YARRICK OPERATING MECHANISM FOR CIRCUIT BREAKERS 5 Sheets-Sheet 1 Filed Oct. 29 1951 INVENTOR 6514245.; A lfvee/cz %%m TTORNEYS July 10, 1956 c. J. YARRICK 2,754,389

OPERATING MECHANISM FOR CIRCUIT BREAKERS Filed Oct. 29, 1951 5 Sheets-Sheet 2 ATTORN EYS y 10, 1956 c. J. YARRICK ,7

OPERATING MECHANISM FOR CIRCUIT BREAKERS Filed Oct. 29, 1951 5 Sheets-Sheet 5 INVENTOR f/MELFJ Xaaercz mwfkJ/yw ATTORNEY6 y 10, 1956 c. J. YARRICK OPERATING MECHANISM FOR CIRCUIT BREAKERS 5 Sheets-Sheet 4 Filed Oct. 29, 1951 INVENTOR 6144x455 Knee/ck BY (9 wfm ATTORN EYJ- July 10, 1956 c. J. YARRICK OPERATING MECHANISM FOR CIRCUIT BREAKERS 5 Sheets-Sheet 5 Filed Oct. 29 1951 @FERATING MECHANISM FOR CIRCUIT BREAKERS Charles l Yarrick, West Collingswood, N. 5., assignor to l-T-E Circuit breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Application (Dctober 29, 1951, Serial No. 253,716 Claims. (Cl. 200-89) The present invention relates to circuit breakers and more particularly to operating features of the components thereof.

The interruption of high currents involving relatively large amounts of power is a hazardous task to personnel and connected equipment unless it is performed under carefully defined conditions. The operator may be injured or k lled by the failure of any one of several components of the breaker. Equipment may be extensively damaged by failure of the circuit breaker to properly perform its function.

Essentially, the novel safety features incorporated in the circuit breaker are in the escutcheon, the operating mechanism, the control relay and the arc chute. The combination of the novel operating features as incorporated in the circuit breaker and as described in the present application provide a very safe interrupter for high currents.

The invention further contemplates the arrangement of a circuit breaker so that it may readily be supported from a steel panel, being electrically isolated therefrom by a plurality of insulating elements each specifically adapted to support a particular unit or assembly on the steel panel.

This circuit breaker is also so constructed that it may readily be operated in a closed steel compartment aligned with a multiplicity of other compartments in a switchboard in which the compartments are in close juxtaposition to each other.

The unit assemblies of which this circuit breaker is constructed comprise essentially a contact structure, a trip unit and are chute assembly, each of which are fitted in o an individual base molding which then is secured to the steel panel. The circuit breaker also comprises the operating mechanism which is largely composed of metal stampings making an economical assembly, a control assembly, and an escutcheon mounting assembly.

it is then a primary object of the present invention to provide a novel and highly safe circuit breaker.

Another object of the invention is the construction of a circuit breaker so arranged that it may be readily manufactured and assembled from a plurality of unit assemblies particularly adapted to be interengaged with each other to form a coordinated circuit breaker assembly.

Another object of the invention is the arrangement of a circuit breaker structure so that the individual elements thereof may readily be supported from a steel panel, each of the individual elements being appropriately insulated from the steel panel by individual insulating supports.

Another object of this invention is the arrangement and construction of a circuit breaker in such manner that each of the parts thereof embraced in individual unit assemblies may readily be interchanged with similar unit assemblies of other circuit breakers so that the circuit breaker construction as a whole is particularly adapted to mass production methods and procedures.

Still another object of this invention is the provision of a steel supporting panel for the parts of the circuit breaker.

tinited Skates Fatent ice A further object of the present invention is the provision of novel operating means for closing and tripping the circuit breaker.

A further object of the present invention is the provision of a novel self-sealing escutcheon upon increase of gas pressure interior to the circuit breaker.

A further object of the present invention is the provision of a control relay having a maintained closing switch.

The foregoing and many other objects of the present invention will become clear from the following description and the accompanying drawings, in which Figure 1 is a front view of the novel circuit breaker of the present invention with the front panel removed.

Figure 2 is a side view of the novel circuit breaker of the present invention.

Figure 3 is a cross-sectional side view of the novel circuit breaker with the contacts open.

Figure 4 is a sectional view of part of the operating mechanism along line 4-4 in Figure 3.

Figure 5 is a sectional view along line 55 in Figure 3 of a portion of the operating mechanism of the circuit breaker of the present invention.

Figure 6 is a partial side cross-sectional view of the novel circuit breaker of the present invention with the contacts closed.

Figure 7 is an exploded view in perspective of the operating mechanism of the novel circuit breaker of the present invention.

Figure 8 is a schematic drawing of the novel operating mechanism of the present invention in the open position.

Figure 9 is a schematic drawing of the novel operating mechanism of the present invention in the trip position.

Figure 10 is a schematic drawing of the operating mechanism of the present invention in the collapsed position.

Figure 11 is a schematic drawing of the operating mechanism in the closed position.

Figure 12 is a wiring diagram of the novel control relay of the present invention.

Referring now to Figures 1 and 2, there is here shown the novel circuit breaker 38 of my present invention. Circuit break r 39 is composed of a plurality of unit assemblies which include the contact structure 31, the arc chute assemblies 32, the operating mechanism 33, control assembly 34 the escutcheon mounting assembly 35 and the trip unit 36.

The circuit breaker 30 as shown in these figures is a three pole circuit breaker in which three contact structures 31 and three are chute assemblies 32 are provided. The contact structures 31 are provided with three stationary contacts and three movable contacts, as hereinafter described. One control assembly 34 is provided for the circuit breaker 30, the unit operating a plunger to close the circuit breaker, as hereinafter described. A single operating mechanism 33 is, however, provided which is used to close and open the circuit breaker contacts. The circuit breaker 3d is supported on a steel panel 40.

The panel iii is a flat steel plate provided with three openings 41. The three openings 41 are aligned horizontally adjacent the upper end of the steel panel 49 and are square shaped. The said openings 41 are pro vided to receive part of the base moldings. Similarly, three rectangular shaped openings 42 are aligned horizontally in the central portion of panel or plate 40. These openings 42 are provided to receive another seating portion of the hereinafter described base moldings.

Still another three openings 43 aligned horizontally at the lower end of the plate 40 are provided which seat another series of protuberances of the base moldings hereinafter described.

In appropriate cases, non-magnetic materials may be used for panel 40, such as non-magnetic steels, aluminum sheets, magnesium sheets, and any other physically strong non-magnetic material.

Smaller openings 48, hereinafter described, are in the steel panel 40 for the reception of various bolts and other securement means for securing the various assemblies and their supports rigidly to the steel panel.

An important feature of the present circuit breaker construction is in the use of a steel panel 40 which acts as part of an enclosure for the bus connections behind this steel panel. The construction of the steel panel 4 and circuit breaker mountings used in connection therewith is particularly adapted for low voltage circuit breakers, for 600 volts or below. In the past this type of breaker has been universally mounted on slate or ebony asbestos panels. In these designs the live parts of the breaker have been spaced on the insulating base so as to provide the proper creepage distance over the insulation. The use of a steel panel is possible only when the moldings are provided with flanges which increase the creepage distance between live parts and the steel panel which is grounded when in a switchgear assembly. By using flanges on the molding it is possible to mount the live parts relatively close together and still get adequate insulation.

The use of a steel panel has been dictated by the requirement that the panel be very much lighter than it was before, particularly on shipboard, where weight is important in the design. Steel is also stronger and not subject to breakage. It is particularly desirable where shock tests are required and breakage of insulating base panels has occurred. Moreover, steel is fireproof. Switchboard fires occurring in the past have resulted in the destruction of the insulating panels. The steel panel also provides a grounded metal barrier between the front of the breaker and whatever is at the rear.

The contact structure 31, referred to above in reference to Figures 1 and 2, is comopsed of a stationary contact assembly 60 and movable contact assembly 61, as shown in Figure 9.

The stationary contact assembly 60 comprises a contact surface 62 which is welded at 63 to one end of the stationary arcing horn 64. Arcing horn 64 is welded to a copper block 66 which together with copper block 67 sandwiches copper plate 68. This assembly is held together by means of the two screws 69 which pass through bar 66 and plate 68 and thread block 67. Copper plate 63 fits into oblong opening 59 and is held rigidly in place by means of two screws 70 shown in Figures 3 and 6.

The copper plate 68 is additionally secured to the base molding 50 by means of an angle 72 as shown in Figure 3. The angle 72 is secured to the base molding 511 in space 54 by means of the screws 70 which pass through angle 72 and the base molding 50 threading the copper block 67 described above. The angle helps to rigidly secure copper plate 68 to the base molding 50 by means of a screw 73 which passes through the plate 68 and threads one side of the angle 72.

The connection is from the buses of the electrical system (not shown) to the three copper plates 68. The other connection to the buses is from copper plates 75. The copper plates 75, one for each pole, are connected through an overcurrent coil 76, hereinafter described, to the movable contacts 61.

Under overcurrent condition, shown dotted in Figure 3, an energized coil 139 aided by a core 141 pulls an armature 142 against itself. The armature 142 comprises two units 143, seen also in Figure 7. The units 143 each have a screw 145 threaded at one end thereof and which is used to effect an adjustable contact with the initial tripping member 140. The head 144 of the screw 145 acts to rotate bar 140 upon the energizing of the coil 139 and hits extension plate 146 which is bolted to the shaft 140 described above. When the head 144 hits the end of the extension plate 146, the shaft 140 is caused to rotate in a counterclockwise manner looking from the right of the circuit breaker 30, which is the view of Figure 7.

The shaft is also caused to rotate by means of a coil 150 which upon being energized pulls an armature member 151 to it. The member 151 has a link 152 rigidly attached to one end 153 of member 151 by means of an angle 154. The link 152 is attached to the angle 154 by means of a threaded portion 199 of link 152 which enters the angle 154 and a nut 148. The angle 154 is movably attached to the member 151 by means of a pin 155. A restoring spring 147 attached to the member 151 resets the armature upon de-energization of the coil 150.

The link 152 is attached to the shaft 140 by means of another angle 156. The angle 156 is attached to the shaft 149 by means of two bolts 158 and to the link 152 by means of a cap 160. The cap 16%) is movably attached to the link 152. Thus, the shaft 141) can now be caused to rotate by two methods, one due to the energization of the overcurrent trip coil 139 and the other due to the energizing of the coil 15%. The coil 15%) is remotely caused to be energized and is usually accomplished by manual operation of a remote pushbutton switch. The rotation of shaft 141 causes a link 162 to be moved by means of an angle 163 which is bolted to the shaft 140 by means of two bolts 164. The angle 163 has an indentation 165 near the farthest edge 166 from the shaft 140. The link 162 has two slots 168 and 167. The slot 167 engages the indentation 165 of angle 163.

The translatory movement of link 162 causes the rotation of a milled shaft 170. The milled shaft 170 has another angle 171 rigidly attached to it by means of two bolts 172. This angle has an indentation 173 near the end 174 which is farthest from the shaft 170. The indentation 173 of angle 171 engages the slot 168 of link 162. Thus the rotation of shaft 146 causes the rotation of milled shaft 170.

When milled shaft 170 rotates to release a latch 177, as is hereinafter described, the circuit breaker movable contacts are allowed to be disengaged from the stationary contacts.

The angle 171 described above has an abutment 178. This abutment 178 is engaged by a roller 179 which is rotated manually by means of the closing handle 184 attached to the shaft 180. Shaft 181) has a crank 181 which is rigidly attached to the shaft by means of a screw 182. The roller 179 is attached to one end of the crank 131. When the shaft 180 is rotated by the closing handle 184 the roller 179 engages abutment 173 of angle 171 and rotated milled shaft 176. Thus milled shaft 170 can be made to rotate by a plurality of methods. It can be made to rotate manually by means of closing handle 184; it can be made to rotate by means of an overcurrent condition in coil 139, as described above;

and it can be made to rotate by means of an excitation of coil 150, as described above.

The latch 177 is an integral part of trip arm 185. The latch 177 engages the milled shaft 179 so that a small revolution of shaft 170 releases the latch 177, as hereinafter described. The shaft 171) is milled slightly past center at 186. The trip arm 185 is pivoted at 187 on a long pin 188. The pin 188 is also engaged on the trip arm extension 189 at point 183. The pin 188 carries a movable arm 190. The movable arm 1% is pivoted on pin 188 at points 191 and 192 and extends beneath a roller 193. The roller 193 is the pivot point of a toggle mechanism consisting of two links 194 and 1% and is carried by a pin 202 which pivots the meeting of links 194 and 195.

The links 194 and 195 each comprise two arms, 194A and 194B, and 195A and 195B, respectively. Arms 194A and 19413 are pivoted on floating pin 196 described above and arms 195A and 19513 are pivoted on pin 2114 also described above.

greases The arm 194A and 194B support a rod 197 at 198 and 199, respectively. The rod 197 carries one end of a restoring spring 203 which is tensed by means of a stationary shaft 212, hereinafter described. The restoring spring 2633 exerts a tension on the link 194 which tends to open or break the toggle mechanism. Link 194 is pivoted on a floating pin 1%, which is supported by link arm and its extension 139 being parallel to the pin 1 .38. The other link 1% of the toggle is pivoted on movable link 2% which is connected by means of an adjustable insulator 2M to the movable contact assembly 61 described above. When the toggle mechanism consisting of links 2.9 3 and 195 is straightened out by means hereinafter described, pressure is put on movable link 200 by means of link 195 and bearing pin 2%. The movable link Ziill is pinned to insulator 251 by a pin 295 and moves so as to advance the insulator 291 and the movable contacts er towards the stationary contact 60.

In the exploded view shown in Figure 7 the contacts are open and the toggle mechanism consisting of links 194- and 195 is collapsed. The circuit breaker may be closed by a variety of methods. The circuit can be closed manually by means of shaft 1% rotated by closing handle described above. If shaft 13?; is rotated in the direction indicated by the arrow 184A, the roller 1'79 will engage the bottom of arm 1% and force the arm 1% against roller 3.53, thus straightening out the toggle mechanism and closing the circuit breaker contacts.

The movable links 2% are under an opening tension by means of opening spring 21% so that if no additional locking action other than described above for supporting the toggle existed, the circuit breaker would re -open im mediately upon releasing the shaft 188. The locking device is supplied by means of a crank 211 which is located on a shaft 212 mentioned above, whose longitudinal axis is parallel to the axis of the milled shaft 176 and the rod The crank 21?. two arms 213 and 214. The arm is located, when the circuit breaker is open, adjacent the roller 193. When the roller 3 .93 is forced upward, as due to the pressure of arm 1%, the roller pushes against arm 213 of crank 211, rotating the crank 211 slightly on shaft 2T2. When the roller 193 has cleared the top of arm 213, the arm 2T3 snaps underneath the roller 1% due to the compression of a spring 22-3. The spring 229 which is wound on the shaft 212 has one end in an indentation 221 of crank 2H and the other end borne against a shaft 222 which pierces the trip arm 185. The shafts and 222 have been moved out of position in the exploded view for the sake of clarity. Actually the shaft 222 pierces the trip arm 185 at point 267. The longitudinal axis of shaft 222 is essentially parallel to the longitudinal axis of shaft 212 and milled shaft 17 When the roller T93 is moved, straightening the toggle, it causes crank Zll to rotate compressing spring 226 The roller clears the top of arm 213 letting the crank rotate in the opposite direction until the arm 213 is directly beneath and supporting the roller 193. The other arm 2.1 or crank Ell bears against the shaft 222 preventing further rotation of the crank 211 so that the arm 213 is stopped directly beneath the roller 1&3. The spring 226 is under compression normally so that the arm 214 is constantly bearing against the shaft 222. When the toggle is straightened, the rotation of the crank 211 moves the arm 2314 away from the shaft 222 until the roller 193 clears the top of arm 213. Then the reverse rotation of the crank 23.1 occurs until the arm 214 again bears against shaft 212.

Thus, when the toggle is straightened and the circuit breaker closed, the crank 2H locks the toggle and thus locks the circuit breaker in a closed position.

The closing handle 184 by means of the shaft 180, after closing the circuit breaker by means of the rotation of roller 179 against the arm 1%, as described above, is returned to its normal position by means of a crank 230. The crank 23% is pivoted on a stationary pin 231.

The crank 181i described above has an indentation 232 which meets a roller 233 of crank 230. The crank 230 supports a pin 234- which has a restraining spring 235 engaged at one end The restraining spring 235 is attached to an angle 237 and is tensed on the pin 236, causing the crank 23-4) to rotate. The rotation of crank 230 causes the roller 233 to meet the indentation 232 returning the crank 131 to its normal position.

The circuit breaker may also be closed by means of a plunger 24% shown also in Figures 3 and 5. The plunger 2% is part of the core of a solenoid coil 241. A remote signal energizes the coil 24-1 and causes the plunger extension Zdr; to push against the roller 193 in a similar manner as the arm 19-3. The roller 193 is a cylinder and has the arm 1% meet it on one-half and the plunger extension meet it at the other half. The plunger extension 2 5d raises the roller 1% straightening out the toggle mechanism and closing the circuit breaker with the locking action due to crank 213i similarly as described in reference to the manual closing of the circuit breaker.

The closing sol noid 241 is energized from a remote point in the following manner.

When the circuit reaker is desired to be closed from a remote point, a button 5th) in Figure 12 is depressed which energizes the relay coil 3%. The energized coil 3% acts as an electromagi t and attracts the movable armature 391, shown in Figure 7. The movable member 3131 is pivoted in three places by pins 362, 393 and 364. The pin 332 is a fixed pivot but the other two pins, 353 and 364, are floating pivots. The pin 3t'i2 also supports an extension 365 of a movable bracket 3%. The extension 395 is secured to the bracket 3% by means of three screws 307. The bracket 36% carries at one end the extension 395 and at the other end a e'shaped contact 398. The contact 363 is movably connected to bracket 3th; by means of two pins 369. The pins are movable with respect to the bracket 3% and the contact 3627. The bracket 3% and the contact are held together by means of the springs 31ft supported ag inst the top of the pins 3-39. The contracted springs 316* force the contact 3&8 against the bracket 3%.

The movable member Bill has a laminated armature 31.2. The laminated armature 312 is rigidly attached to the member by means of force fit pins 313 and 314. The movable member 3121 has also as an integral part thereof an angle, not shown, which bears a dielectric rectangular strip 315.

When the coil 3% is energized, the bracket 396 brought closer to he coil making strip 315 just touch a contact 316, shown in Figure 2.

Once coil 3th) is energized, the movable member 3% carrying the bracket 3% is locked against coil Still, as is hereinafter described, obviating the further energization of coil 3% Thus, touching the remote button, not shown, but briefly, is suthcient to lock the mechanism described against the coil 3%.

When coil 3% is energized, it energizes in solenoid coil 24?. described above, causing extension 2 h! to plunger extension sectionally square turn closing the plunger move against the roller 193. the 2-2 9 carries at its distal end a crosscore 320 which slides into opening member 322-. As the plunger completes the closing of the circuit break r by means of pushing roller 193 onto arm 213, as described above, the member 329 engages the head 323 of a screw The screw 324 is carried by a link 32%, which is pivoted by a floating pin 3tl4 of the movable member The link 325 normally rests against a pin 326 carried at one end of a tray-like member 327. The member 327 is pivoted at its other end on a floating pin 328 which also pivots the end of the extension 3% described above. Pin 363 and pin 32% carry springs not shown which are tensed to pin 326.

The control relay, as described above, maintains the relay contact 3% in a substantially latched position with 7 the armature 3% under normal conditions. Upon energization of the coil 3%, the armature 391 moves to its closed position carrying the contact 338 with it. The engagement of the movable relay contact 3498 with the stationary relay contacts 552 shown in Figure 7 establishes the circuit of the closing solenoid.

Referring again to the circuit diagram as shown in Figure 12, the closing of the remote switch energizes the coil 361 through the normally closed contacts 5&3 and resistor 564. The energization of coil 3% energizes coil 241 and closes the contacts 348 and 5% described above.

When the head 323 is hit by member 322 the mechanism shifts, causing the opening of the circuit deactivating coils 3G9 and 241. The closing solenoid plunger 240 will open the latch engagement between the relay armature 367 and the relay contacts 343 when the closing solenoid plunger 24% nears its completion of the closing stroke. This allows the closing solenoid 3% electrical circuit to be interrupted when the circuit breaker 30 is securely latched in the closed position. the relay operating switch 531) is held in the closed position, the relay operating coil 3% will hold the relay armature 361 in sealed position while the relay contacts 3% remain in the open position. The relay armature 301 and the relay contacts 343 cannot relatch until the relay closing switch Silt) is released. This operating characteristic makes the relay trip free. Continuous pumping of the circuit breaker closing mechanism is thus prevented using a maintained contact close switch under conditions when a fault remains on the circuit or where defective closing mechanism causes defective latchmg.

The various positions of the operating mechanism are shown in Figures 8 through 11.

Figure 11 shows the closed position thereof, with link 311 pushed forward to raise the crank 2% and close the contact arm or insulator 201 and with the roller 193 on the arm or abutment 213.

The latch arm 185 is shown in appropriate latching engagement with the milled shaft 170.

When the shaft 1813 described above is turned to release the mechanism, the condition as shown in Figure results.

On the occurrence of tripping conditions the milled shaft 170 is rotated to permit the latch arm 185 to move into the milled section of position 186 of the milled shaft 170 as seen in Figure 9.

Then as seen in Figure 10 the roller 193 drops off the abutment 213 to open the circuit breaker.

Thereafter as seen in Figure 11, the latch arm 185 is restored to its initial position and the milled shaft 17% is restored to latching position so that the circuit breaker may again be moved from the open position of Figure 8 to the closed position of Figure 11.

The closing handle 134 returns to its neutral position automaticaly after tripping or closing the contacts unless it is latched as is hereinafter described. it becomes important to provide for some indication preferably visual of the contact position.

An external indication as to whether the circuit breaker St is open or closed is provided above the closing handle 184 by means of visual indicator 4% shown in Figures 3 and 6. The visual indicator 4% is directly driven as is hereafter described by the movement of the links 200 described above which moves whenever the circuit breaker opens or closes.

Referring now to Figures 3 and 6, the end 4491 of the link 2% has two holes 4192. The link 2% by means of the screws 463 and the nuts 454- through the holes 402 support the plates 4i35. The link 2% rotates on the bar 4% which is partially rectangular and partially circular in cross-sectioned shape. The rectangular cross-sectional shape of the bar 496 passes through the opening 437 in the link 200 and circular portion of the bar 4% is supported on the housing 493 of the circuit breaker 30.

As long as 8 Thus, the bar 406 rotates easily in its supports on the housing 408 carrying with it the links 200 without any slippage.

The plate 405 carries a pin 406 which moves essentialiy up or down dependent upon whether the circuit breaker is opening or closing, respectively. The pin 4139 engages a link 410 through the opening 411. The link 410 carries a pin 412 at its other end which is supported on a sliding member 413. Sliding member 413 has attached to it a spring 414. The other end of the spring 414 is attached to the indicator-carrier 415. The carrier 415 has the two words Open and Closed thereon; the word Open being indicated at 416 and the word Closed at 417. The other end of the indicator-carrier 415 is provided with a notch 416 which pivots on the pin 417. The movement of the words Open and Closed at 416 and 417 is then a circular motion. The front face 418 is spherically shaped. The spherical shape of the face 418 allows good visibility from the sides, top and bottom.

The visual design as described above is directly driven through the links 200, the arms 435, the link 41%, and the sliding member 14 and is thus independent of operation by means of a spring whose failure is the usual cause of a false indication.

Rotation of the closing handle 184 in a counterclockwise direction will cause the locking bar 42% to be rotated to such a position that the locking tip 423 will enter the notch 427. As long as the tip 423 is seated in the notch 427, the circuit breaker 31 cannot be closed. The locking bar 420 is provided with a slot 42% having a sufiicient width to permit the passing of a hasp of a padlock 43% therethrough. This is an important safety facter in the use of the present circuit breaker as unauthorized personnel are thus restrained from closing the breaker.

The handle 184 is seated against the circular portion 424 described above which is an integral part of the escutcheon 425. The escutcheon 425 and the handle 184 are the only portions of the circuit breaker which can be viewed by the operator. The escutcheon has a selfaligning plate 431. The plate 431 is aligned by means of two springs 432 which are coiled on the sliding pins 433. The pins 433 are fixed to the plate 431 at 435 and slide through the bars 435. The bars 435 are held rigidly in place against the back of the escutcheon 425 by means of screws 437.

The escutcheon plate 431 is then self-aligning in that any reasonable deviation in its alignment with the front hinged enclosure 440, shown in Figures 3 and 6, is automatically compensated for by the design. The design provides a safety factor in that gas pressures originated inside the circuit breaker enclosure tend to establish a sealing effect by forcing the escutcheon plate 431 against the cover 440 and thus preventing exposure of the operator to dangerous flare-ups.

In the foregoing the invention has been described solely in connection with specific illustrative embodiments thereof. Since many variations and modifications of the invention will now be obvious to those skilled in the art, it is preferred to be bound not by the specific disclosures herein contained but only by the appended claims.

I claim:

1. An operating mechanism for circuit breakers associated with a movable contact having a circuit closing and a circuit opening position comprising spring means for normally urging said movable contact to opening position; a toggle mechanism having a collapsed and a set position, link members and a latch mechanism having a locking position for normally locking said movable contact in closing position and also having a tripped position; said toggle mechanism, latch mechanism and spring being insulated from sm'd movable contact by means of said link members; said latch mechanism including a milled shaft, a trip arm having a latch, and a movable arm, said latch being urged into contact with said milled shaft when said movable contact is closed and operative upon the angular rotation of said milled shaft to effect movement of said movable contact to open position; said toggle mechanism including two links and a pivot roller, one end of said toggle mechanism being pivotally connected to said latch mechanism at a point eccentric of the pivotal mounting of the latch the other end of said toggle mechanism being pivotally connected to the operating arm of said movable contact, manual means for opening and closing said circuit breaker comprising a handle, a shaft and a roller; said roller secured to said shaft, said handle connected to cause rotation of said shaft and roller in a first and second direction when moved in a first and second direction, respectively; said handle, roller and shaft rotation in said first direction eifective to move said movable contact to open position and in said second direction to move said movable contact to closed position, said handle movement in a first direction effecting contact engagement by moving said toggle pivot roller from a collapsed to a set position by means of said roller and shaft, said handle movement in a second direction effecting contact disengagement by rotating said milled shaft by means of said shaft and roller.

2. An operating mechanism for circuit breakers associated with a movable contact having a circuit closing and a circuit opening position comprising spring means for normally urging said movable contact to opening position; a toggle mechanism having a collapsed and a set position, link members, and a latch mechanism having a locking position for normally locking said movable contact in closing position and also having a tripped position; said toggle mechanism including two links and a pivot roller, one end of said toggle mechanism being pivotally connected to said latch mechanism at a point eccentric of the pivotal mounting of the latch, the other end of said toggle mechanism being pivotally connected to the operating arm of said movable contact, automatic closing means for closing said circuit breaker comprising a solenoid and plunger extension, said plunger extension positioned and controlled by the energization of said solenoid, said pivot roller positioned by said plunger extension when said solenoid is energized to move said toggle mechanism to said set position, manual means for closing said circuit breaker comprising a handle, a shaft and a roller; said handle connected to cause contact engagement by moving said toggle from a collapsed to set position by having said shaft and roller act on said toggle pivot roller.

3. An operating mechanism for circuit breakers associated with a movable contact having a circuit closing and a circuit opening position comprising spring means for normally urging said movable contact to opening position; a toggle mechanism having a collapsed and a set position, link members and a latch mechanism having a locking position for normally locking said movable contact in closing position and also having a tripped position; said link members comprising insulator connectors having protruding flanges extending their insulating capacities; said flanges being circular in cross-section transverse to the main axis of said links; said toggle mechanism including two links and a pivot roller, one end of said toggle mechanism being pivotally connected to said latch mechanism at a point eccentric of the pivotal mounting of the latch, the other end of said toggle mechanism being pivotally connected to the operating arm of said movable contact, automatic closing means for closing said circuit breaker comprising a solenoid and plunger extension, said plunger extension positioned and controlled by the energization of said solenoid, said pivot roller positioned by said plunger extension when said solenoid is energized to move said toggle mechanism to said set position, manual means for closing said circuit 10 breaker comprising a handle, a shaft and a roller; said handle connected to cause contact engagement by moving said toggle from a collapsed to set position by having said shaft and roller act on said toggle pivot roller.

4. A circuit breaker including a control relay, manual operating means, a movable and a stationary contact, and operating means associated with-said movable contact having a circuit closing and a circuit opening position comprising spring means for normally urging said movable contact to opening position; a toggle mechanism having a collapsed and a set position, link members and a latch mechanism having a locking position for normally locking said movable contact in closing position and also having a tripped roller; one end of said toggle mechanism being pivotally connected to said latch mechanism at a point eccentric of the pivotal mounting of the latch, the other end of said toggle mechanism being pivotally connected to the operating arm of said movable contact, said pivot roller being moved to a closed position by said manual operating means and said control relay.

5. A circuit breaker including a control relay, manual operating means, a movable and a stationary contact, and operating means associated with said movable contact having a circuit closing and a circuit opening position comprising spring means for normally urging said movable contact to opening position; a toggle mechanism having a collapsed and a set position, link members and a latch mechanism having a locking position for normally locking said movable contact in closing position and also having a tripped position; said toggle mechanism including two links and a pivot roller, one end of said toggle mechanism being pivotally connected to said latch mechanism at a point eccentric of the pivotal mounting of the latch, the other end of said toggle mechanism being pivotally connected to the operating arm of said movable contact; said control relay having a plunger moved in response to a remote signal; said latch mechanism including a milled shaft, a trip arm having a latch, and a movable arm, said latch being urged into contact with said milled shaft when said movable contact is closed and operative upon the angular rotation of said milled shaft to effect movement of said movable contact to open position; said manual operating means comprising an operating handle and a roller, said roller positioned by said operating handle, said plunger of said control relay and said roller of said manual operating means being positioned to move said pivot roller of said toggle mechanism to eifect the closing of said movable and stationary contacts.

References Cited in the file of this patent UNITED STATES PATENTS 721,410 Wood Feb. 24, 1903 827,469 Scott July 31, 1906 973,938 Harris Oct. 25, 1910 1,190,060 Wolff July 4, 1916 1,199,437 Smith et a1. Sept. 26, 1916 2,152,453 Atwood et al. Mar. 28, 1939 2,177,014 Austin Oct. 24, 1939 2,246,298 Dyer et al. June 17, 1941 2,348,228 Scott May 9, 1944 2,515,994 Findley et al July 18, 1950 2,537,618 Bourne Jan. 9, 1951 2,566,866 Yarrick Sept. 4, 1951 2,549,441 Favre Apr. 17, 1951 FOREIGN PATENTS 415,387 Great Britain Aug. 21, 1934 61,073 Switzerland Mar. 30, 1912 478,172 Germany June 20, 1929 

